1. Field of the Invention
The present invention relates to an ammonia refrigeration unit with a fully packaged construction including an evaporative condenser, a compressor and an ammonia piping system, and particularly, to an evaporative-cooling condensation type ammonia refrigeration unit with leaked ammonia gas removing means.
2. Description of the Prior Art
A condenser-integrated refrigerator, in which a compressor and a condenser are combined in an integrated manner, and which is installable outdoors, has widely been employed, since i) a machine room is not necessary for installation, ii) only a two-way piping is required between a refrigeration unit and a load side, iii) not only can an installment space be saved but field piping work can also be lessened, v) a trial run can be conducted prior to shipment and less work is thereby required in the on-site start-up and the like.
An example of the refrigerator in which a compressor and a condenser is combined in an integrated manner is disclosed in the publication of Examined Japanese Utility Model Application No. Sho 56-5025. The invention, as seen in FIG. 6, comprises: an evaporative condenser 50 including a condenser 52 in which a heat transfer coil is its major constituent, water spray nozzles 58 for spraying cooling water over the condenser 52, a cooling water tank 53, a cooling wafer feed pipeline 59 and a suction blower 63; a compressor 57; a refrigerant pipeline 60; a cold water source 54; a water supplement pipeline 61 and the like, wherein such constituents are assembled in an integrated construction as a unit and accommodated in the same casing 51.
With such a construction of the integrated unit, external cooling loads 68, 68, 68 and an external water supply system 65 are connected with the unit by a pipeline 67 through pipeline connection terminals 64, 64 provided on a wall portion of the casing 51, whereby the field piping work is lessened to an extent as low as possible.
In the case where ammonia is employed as refrigerant, there are risks leading to serious problems in terms of toxicity and combustibility of the material since, according to a report from a research institute, a human being is badly affected in the atmosphere with an ammonia concentration in the range of from 0.5 to 1%: a life is lost or serious disturbance is caused in the body on a 30 min period exposure and explosion limits are established to be from 16 to 25% by volume content, which shows that leakage is easy to cause explosion or human related accidents. In order to avoid a chance of explosion induced accident or restrict it to a minor level, there has been a trend prevailing in very recent years that refrigerators using ammonia as refrigerant are distributed among locations spaced from one another and that ammonia piping is confined within each refrigeration unit which has been distributed.
Even in a refrigeration unit whose safety has seemingly be secured by locating it from another unit in a spaced manner, however, a safety measure for a human being in terms of toxicity and combustibility in the case of leakage of ammonia has not yet been established.